A plug-in hybrid work vehicle includes a first battery charged from an on-board electric generator, a second battery charged from an external electric power source, a charging switch, a DC-to-DC converter, a voltage determination unit, and a charging control unit. During charging from the external electric power source, the charging control unit charges the second battery from the external electric power source when the voltage determination unit determines that the voltage of the first battery exceeds a reference voltage value necessary for starting an engine, and charges the first battery from the external electric power source via the DC-to-DC converter and the like, in preference to charging of the second battery, when the voltage determination unit determines that the voltage of the first battery is equal to or lower than the reference voltage value.